Liquid culture apparatus

ABSTRACT

An apparatus for effecting the liquid culture of a plant body (T) implanted on a nutrient broth medium with the nutrient broth medium permeating a nutrient broth support (10) formed of a porous or fibrous material. At this juncture, the nutrient broth support (10) is accommodated in a nursery chamber (20) maintained in an aseptic state, and is placed on a liquid impregnation/drainage controller (60) having the function of transmitting and receiving (replacing) the liquid, inside the nursery chamber (20) The liquid impregnation/drainage controller (60) causes the liquid (mainly a nutrient broth) supplied from an external nutrient broth supplying device (50) to be supported (impregnate)the nutrient broth support (10) placed. At the same time, the liquid impregnation/drainage controller (60) discharges the liquid supported by the nutrient broth support (10) by making use of, for instance, the capillary phenomenon or the like in correspondence with the state of its draining portion (62). The nutrient broth supplied to the plant body (T) is automatically replaced via the nutrient broth support (10) by making use of the liquid replacing function of the liquid impregnation/drainage controller (60).

TECHNICAL FIELD

The present invention relates to the breeding of plants and productionof seedlings by means of plant tissue culture as well as acclimatizationof grown seedlings, and more particularly to a liquid culture apparatusfor breeding, production of seedlings, and the like by means of liquidculture without using an agar medium.

BACKGROUND ART

The tissue culture of plants is utilized for numerous purposes such asthe large-scale proliferation of virus-free strains and elite plants andproduction of new plant varieties. In conventional tissue culture, amainstream method has been one using the so-called agar medium in whicha prescribed medium solution having a fixed composition is formed byagar as its medium.

FIG. 11 diagrammatically shows tissue culture using the agar mediumcontaining nutrients. That is, in such tissue culture, a plant tissue(see FIG. 11(a)) removed by being cut from a plant is first placed inthe agar medium in a container and is proliferated therein (see FIG.11(b)). The germinated tissue is further divided by being cut (see FIG.11(c)), and is then transplanted in a rooting agar medium in anothercontainer and undergoes rooting therein (see FIG. 11(d)). The plantwhich has thus rooted is removed from the contained, and the agarattached to its root is washed away (see FIG. 11(e)). Subsequently, theplant is moved into an acclimatizer (see FIG. 11(f)). In thisacclimatizer, re. rooting is promoted in a highly humid environment withlight shielded. Finally, a seedling thus grown is removed from theacclimatizer and is acclimatized to the external environment (see FIG.11(g)).

Thus, in the conventional tissue culture, in each stage ofproliferation, germination, and rooting, separate agar media containingmost suitable components are used. Accordingly, it is true that suitablenutrition corresponding to its growth stage is constantly supplied tothe plant, and that favorable results are attained. On the other hand,for that purpose, the aforementioned transplanting operations arerequired in each stage of culture, and in cases where the nutrition inthe agar are lacking, the plant needs to be transplanted in new agar,thereby involving substantial manpower and cost. Incidentally, such atransplanting operation is conducted in an aseptic state.

In addition, in the above described conventional plant culture, at thetime when the young seedling which has rooted is subjected toacclimatization to the outside, it is necessary to transplant it to animplantation medium such as vermiculite or the like. At that juncture,since sugar is contained in the aforementioned agar medium, the portionof its root is usually washed with water, as described above, for thepurpose of preventing the occurrence of mold. On the other hand,however, there arise problems in that the root is liable to becomedamaged and that its growth is delayed. It goes without saying that thetrouble and cost required for washing and transplantation cannot beignored.

Furthermore, in the above-described conventional method, the root whichhas developed in the medium is liable to lapse into a state of oxygenshortage, and therefore there are many cases where the plant fails toelongate sufficiently and become teratomatic. Moreover, with thisconventional method, the replacement, replenishment, and discharge ofthe medium during culture are impossible, and therefore it is impossibleto constantly optimize the gas and components of the medium.

The present invention has been devised in the light of theabove-described circumstances in tissue culture, and the object of thepresent invention is to provide a liquid culture apparatus which iscapable of constantly maintaining the above-described plant tissue(hereinafter referred to as the "plant body" as a generic term for thetissue as well as an adventitious embryo of a shoot primordium intowhich the tissue has grown) in an optimum environment without requiringany operations such as transplantation in the course of cultureincluding implantation, germination, and rooting, as well asacclimatization to the outside, and which in the end is capable ofattaining high-speed, large-scale production at low cost on a stablebasis.

DISCLOSURE OF THE INVENTION

In accordance with the present invention, on the premise of thefostering of seedlings by means of liquid culture, there is provided aliquid culture apparatus comprising: a nutrient broth support forimplantation of a plant body therein and constituted by a porous orfibrous material capable of being impregnated with a nutrient broth; anursery chamber for accommodating at least one nutrient broth support;first liquid controlling (liquid-supply controlling) means fortransferring and supplying a liquid to the nursery chamber; secondliquid controlling (impregnation and drainage controlling) means whichis constituted by a water absorbent material having a smaller porositythan the nutrient broth support and is disposed at a bottom of thenursery chamber as a member for placing the nutrient broth supportthereon, the second liquid controlling means being connected to thefirst liquid controlling means and arranged such that when the liquid issupplied by means of the first liquid controlling means, the secondliquid controlling means causes the nutrient broth support to beimpregnated with the liquid supplied, and when the supply of the liquidis being suspended, the second liquid controlling means drains theliquid impregnating the nutrient broth support; and third liquidcontrolling (drainage controlling) means connected to the second liquidcontrolling means and adapted to drain the liquid circulated via thesecond liquid controlling means to outside the nursery chamber.

By virtue of this arrangement, if, for instance, a germination nutrientbroth containing effective components for the germination of the plantbody implanted in the nutrient broth support is transferred and suppliedto the nursery chamber as the aforementioned liquid, this germinationnutrient broth is supported by (impregnates) the nutrient broth supportas a nutrient broth medium, thereby automatically allowing the plantbody to be placed in a favorable environment for germination. Inaddition, if a rooting nutrient broth containing effective componentsfor the rooting of the plant body is transferred and supplied to thenursery chamber, this rooting nutrient broth is supported by(impregnates) the nutrient broth support as the nutrient broth medium,thereby automatically allowing the germinated plant body to be placed ina favorable environment for rooting. Furthermore, if a cultivationnutrient broth containing effective components for the fostering of theplant body and not containing sugar is transferred and supplied to thenursery chamber, this cultivation nutrient broth is supported by(impregnates) the nutrient broth support as the nutrient broth medium,thereby automatically allowing the rooted plant body to be placed in afavorable environment for the production of the seedling andacclimatization to the outside.

Accordingly, by consecutively and selectively transferring and supplyingthe respective nutrient broths in correspondence with the growth stageof the plant body, it becomes possible to realize breeding, fostering ofseedlings, acclimatization of grown seedlings, and the like constantlyin an optimum environment for the plants without requiring anytroublesome operations mentioned above such as transplanting.

Also, at the time of replacing the nutrient broth to be supported by thenutrient broth support, if pure water is used as the aforementionedliquid to be transferred and supplied, it becomes possible toautomatically wash the nutrient broth support.

In particular, the nutrient broth support and the second liquidcontrolling means mentioned above are provided with structures suitablefor the transmission and reception of such a liquid (automaticimpregnation and draining thereof in correspondence with the liquidlevel).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an overall arrangement of afirst embodiment of a liquid culture apparatus in accordance with thepresent invention;

FIG. 2 is a top plan view schematically illustrating the mode in whichnutrient broth supports are stored in a nursery chamber in the apparatusof the embodiment;

FIG. 3 is a block diagram illustrating an example of the arrangement ofan implanting device of the apparatus of the embodiment shown in FIG. 1;

FIG. 4 is a schematic diagram illustrating the arrangement of essentialportions of a second embodiment of the liquid culture apparatus inaccordance with the present invention.

FIG. 5 is a schematic diagram illustrating the arrangement of essentialportions of a third embodiment which is a modification of the secondembodiment;

FIG. 6 is a schematic diagram illustrating the arrangement of essentialportions of a fourth embodiment which is a further modification of thesecond or third embodiment;

FIG. 7 is a schematic diagram illustrating the concept of thearrangement of a fifth embodiment of the liquid culture apparatus inaccordance with the present invention;

FIG. 8 is a schematic diagram illustrating an example of the arrangementof the fifth embodiment;

FIG. 9 is a schematic diagram illustrating an overall arrangement of asixth embodiment of the liquid culture apparatus in accordance with thepresent invention;

FIG. 10 is a schematic diagram illustrating an overall arrangement of aseventh embodiment of the liquid culture apparatus in accordance withthe present invention; and

FIG. 11 is a schematic diagram diagrammatically illustrating the stepsof processing of the conventional plant tissue culture using the agarmedium.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 illustrates an overall arrangement of a first embodiment of aliquid culture apparatus in accordance with the present invention.

As shown in FIG. 1, the apparatus of this embodiment comprises thefollowing components: a plurality of nutrient broth supports 10 whichare formed of a porous or fibrous material with excellent waterretentivity and air permeability, and in which plant bodies T subject toculture are implanted; a nursery chamber 20 in which the nutrient brothsupports 10 are accommodated via a carrying in-and-out port 21 which canbe hermetically closed; an implanting device 30 and an implantingmechanism 40 for implanting the plant bodies T subject to culture on therespective nutrient broth supports 10 accommodated and arranged in thisnursery chamber 20; a nutrient broth supplying device 50 whichincorporates a tank for storing in an aseptic state nutrient broths suchas a germination nutrient broth containing effective components for thegermination of the plant bodies T, a rooting nutrient broth containingeffective components for the rooting of the plant bodies T, and acultivation nutrient broth (not containing sugar) containing effectivecomponents for growing the plant bodies T, and pure water or the likefor washing which will be described later, the nutrient broth supplyingdevice 50 being adapted to selectively deliver these nutrient broths orpure water by means of a pump or the like; a liquid transfer device 51constituted by a pipe product or the like and adapted to transfer andsupply to the nursery chamber 20 the nutrient broths or pure water thusdelivered; a liquid impregnation/drainage controller 60 which isdisposed as a member for placing thereon the nutrient broth supports 10in the nursery chamber 20 as shown in the drawing, a liquid supplyingportion 61 at one end thereof being connected to the transfer device 51;and the liquid impregnation/drainage controller 60 being arranged suchthat when the nutrient broth or pure water is supplied by means of thetransfer device 51, the liquid impregnation/drainage controller 60causes the nutrient broth support to be impregnated with the nutrientbroth or pure water supplied, and when the supply of the nutrient brothor pure water is being suspended, the liquid impregnation/drainagecontroller 60 drains the liquid impregnating the nutrient broth supports10; a draining portion 62 disposed at the other end of the liquidimpregnation/drainage controller 60 and adapted to drain the nutrientbroths or pure water thus transmitted or received, to outside thenursery chamber 20; a circulator 52 for causing the drained liquid toreturn to the tank disposed in the nutrient broth supplying device 50; agas supplying device 70 which incorporates a gas mixer for mixing theair and carbon dioxide (CO²) at a predetermined ratio (e.g., the airincludes not less than 250 ppm of CO²) and which is adapted to deliverthe gas mixture via a bacteria-proof filter or the like and afteradjusting the temperature and humidity thereof to predetermined levels;a gas transfer device 71 constituted by a pipe product or the like andadapted to transfer and supply the delivered gas into the nurserychamber 20; a gas exhausting device 72 adapted to exhaust in an asepticstate the gas supplied into the nursery chamber 20 to outside thenursery chamber 20, as required, so as to maintain the interior of thenursery chamber 20 in the environment of a fresh gas; an illuminator 80having a known light-adjusting device and adapted to supply appropriatelight into the nursery chamber 20; and a sterilizer 90 for effectingsterilization by heating the interior of the nursery chamber 20 or usinga bactericidal gas.

Here, as the aforementioned nutrient broth supports 10, it is possibleto use polyester wool, ceramic wool, rock wool, peat moss, vermiculite,glass wool, cellulose, or the like, and these are accommodated, asrequired, in appropriate containers 11 which are bottomless or whosebottoms are constituted by a wire net or the like, and are used as thenutrient broth supports 10. In addition, these nutrient broth supports10 are accommodated and arranged two-dimensionally in the nurserychamber 20 (to be precise, on the liquid impregnation/drainingcontroller 60 in its interior) in the manner such as the one shown inFIG. 2.

In addition, the implanting device 30 and the implanting mechanism 40mentioned above are arranged in the manner such as the one shown in FIG.3.

In FIG. 3, reference numeral 31 denotes a controller for effectinggeneral control of the operation of the implanting device 30 and theimplanting mechanism 40; 32, a tank in which the plant bodies T (here,their seeds) are stored; 33, a first valve used for loading the plantbodies T in this tank and also having the function of maintaining theinterior of the tank 32 in an aseptic state; 34, a second valve whichopens and closes on the basis of control by the controller 31; 35, aflexible hose; 36, a pump for transferring to the hose 35 the plantbodies T sent from the tank 32 via the second valve 34; 37, a firstmotor for actuating the pump 36 on the basis of control by thecontroller 31; 38, a tissue sensor for detecting the sending of theplant bodies T to the hose 35 and outputting a detection signal to thecontroller 31 to that effect; and 39, a nozzle fixed to the tip of thehose 35. In addition, numerals 41a and 41b denote first railsrespectively disposed in the direction of Y--Y in the nursery chamber 20(in a direction perpendicular to the plane of the drawing) in the mannershown in FIGS. 1 and 3, and 42a and 42b denote first rollers for movingon the first rails 41a and 41b in the direction of Y--Y, respectively.Numeral 43 denotes a second rail disposed in the direction of X--X inthe nursery chamber 20 by being supported between the rollers 42a and42b in the illustrated manner; 44, a second motor for rotatively drivingthe roller 41a on the basis of control by the controller 31 so as tomove the second rail 43 integrally in the direction of Y--Y; 45, asecond roller for moving in the direction of X--X on the second rail 43;46 an arm affixed to the second roller 45 and adapted to support thenozzle 39; and 47, a third motor for rotatively driving the roller 45 onthe basis of control by the controller 31 so as to move the arm 46,i.e., the nozzle 39 supported thereby, in the direction of X--X.

That is, of the implanting device 30 and the implanting mechanism 40,the implanting device 30 on the one hand is arranged such that, on thebasis of detecting of the sending of the plant bodies T (seeds) by thetissue sensor 38 on each such occasion, the controller 31 actuates thepump 36, while controlling the opening and closing of the second valve34, and in synchronism therewith as required, whereby the plant bodies T(seeds) stored in the tank 32 are discharged positively one by one viathe hose 35 and its nozzle 39. The implanting mechanism 40, on the otherhand, is arranged such that, the controller 31 controls the driving ofthe second and third motors 44 and 47 in a predetermined manner insynchronism with the discharging of the plant bodies T, whereby thetwo-dimensional coordinate position of the nozzle 39 in the directionsof Y--Y and X--X is moved consecutively in correspondence with thearrangement of the nutrient broth supports 10, as shown in FIG. 2. Inother words, the implanting device 30 and the implanting mechanism 40thus arranged make it possible to effect the consecutive automaticimplanting of the plant bodies T one by one on the respective nutrientbroth supports 10 in correspondence with the two-dimensional scanning ofthe nozzle 39 over the nutrient broth supports 10 with the Y--Ydirection set as the main scanning direction (or the sub scanningdirection) and the X--X direction set as the sub scanning direction (orthe main scanning direction).

In addition, with the apparatus of this embodiment shown in FIG. 1, theliquid impregnation/drainage controller 60 has its upper surface formedof a material, such as cotton, having a smaller porosity than that ofthe nutrient broth supports 10 so that the transmission and reception(impregnation and drainage) of the aforementioned liquid will beeffected favorably between the same and all the nutrient broth supports10 while the liquid impregnation/drainage controller 60 functions as amember for placing the nutrient broth supports 10 thereon. In addition,the liquid impregnation/drainage controller 60 functions to support theliquid (nutrient broth or pure water) supplied thereto to be supportedin (impregnates) the nutrient broth supports 10 in correspondence with arise in the level of that liquid, and also functions to prompt thedraining of the liquid supported in (impregnating) the respectivenutrient broth supports 10 in correspondence with the suspension of thesupply of the liquid or a drop in the liquid level. That is, control ofthe water content in the nutrient broth supports 10 is realized byvirtue of this impregnating/draining action of the impregnating/drainingcontrol device 60 capillarily connected to the nutrient broth supports10. The liquid drained from the nutrient broth supports 10 and returnedto this impregnating/draining control device 60 is also drained tooutside the nursery chamber 20 via the draining portion 62 disposed atthe tip of the impregnation/drainage controller 60.

The processing procedures of liquid culture conducted by using theembodiment of the first embodiment will be listed below.

(1) First, the carrying in-and-out port 21 is opened, and the nutrientbroth supports 10 (where required, including the containers 11) areaccommodated and arranged on the liquid impregnation/drainage controller60 inside the nursery chamber 20.

(2) Then, the carrying in-and-out port 21 is hermetically closed, andthe entire interior of the nursery chamber 20 is sterilized by means ofthe sterilizer 90.

(3) After sterilization, the internal environment of the nursery chamber20 is returned to the normal state, and the plant bodies T (seeds) areimplanted with respect to all the accommodated nutrient broth supports10 by means of the implanting device 30 and the implanting mechanism 40.At this juncture, the aseptic state of the plant bodies T (seeds) ismaintained by virtue of the above-described arrangement of theimplanting device 30.

(4) Upon completion of implantation, the germination nutrient broth issupplied to the nursery chamber 20 by means of the nutrient brothsupplying device 50 and the transfer device 51. As a result, thegermination nutrient broth is supported by (permeates) the respectivenutrient broth supports 10 as a nutrient broth medium through theaforementioned operation of the liquid impregnation/drainage controller60. In addition, in conjunction with the supply of the nutrient broth,the supply of gas with predetermined components and at predeterminedtemperature and humidity is effected by means of the gas supplyingdevice 70 and the transfer device 71, and the supply of predeterminedlight is effected by means of the illuminator 80. By placing the nurserychamber 20 in such an environment, the implanted plant bodies T (seeds)undergo germination with the lapse of time.

(5) When desired germination is thus obtained, the supply of thegermination nutrient broth by means of the nutrient broth supplyingdevice 50 and the transfer device 51 is stopped and, instead of thisgermination nutrient broth, the supply of pure water by means of thenutrient broth supplying device 50 and the transfer device 51 iseffected for an appropriate time. As a result, the nutrient brothsupports 10 are washed through the aforementioned operation of theliquid impregnation/drainage controller 60.

(6) After washing, the aforementioned rooting nutrient broth is thensupplied by means of the nutrient broth supplying device 50 and thetransfer device 51. As a result, the rooting nutrient broth is newlysupported on (impregnates) the nutrient broth supports 10 as a nutrientbroth medium. The plant bodies T placed in this environment undergorooting with the lapse of time, as described above. At this juncture aswell, the aforementioned gas and light are adjusted so as to be suitablefor the environment for such rooting.

(7) When desired rooting is thus obtained, the washing of the nutrientbroth supports 10 is effected in a manner similar to that of processingin step (5) above. In particular, washing is important in removingnutrients such as sugar contained in the germination nutrient broth.

(8) After washing, the aforementioned cultivation nutrient broth issupplied by means of the nutrient broth supplying device 50 and thetransfer device 51. As a result, the cultivation nutrient broth is newlysupported on (impregnates) the respective nutrient broth supports 10 asa nutrient broth medium in the same way as before. In addition, in thisprocess, an attempt is also made to reduce the humidity of the interiorof the nursery chamber 20 in correspondence with the growth of theseedlings with a view to acclimatization to the external environment.

(9) By timing a stage at which the plant bodies T have developed intogrown seedlings, they are removed from the carrying in-and-out port 21.

The processing of steps (1) to (9) above is repeatedly carried out.

Thus, in accordance with the apparatus of this embodiment, culture suchas the implantation, germination, and rooting of the plant bodies aswell as their acclimatization to the outside can naturally be effectedin a state in which the material (nutrient broth supports 10) carried infrom the outside is set in a sterile, aseptic state, and the componentsof the nutrient broths, gas components, light, temperature, and humiditycan be controlled to optimum levels in the respective stages of culture.In addition, by continuously employing the identical nutrient brothsupports in the respective stages of culture, the transplantingoperation and the like involving manpower are not required at all.Accordingly, the root which has developed is not subjected to damage.

The washing processing in the aforementioned step (5) is not necessarilyrequired in that stage, but if it is implemented, a situation in whichthe germination nutrient broth and the rooting nutrient broth are mixedin the nutrient broth supports 10 is obviated favorably in the initialstage of the supply of the rooting nutrient broth (processing in thestep (6) above).

FIG. 4 illustrates a structure of essential portions of an apparatus inaccordance with a second embodiment of the present invention. Thissecond embodiment is an improvement and an embodiment of the structureof the liquid impregnation/drainage controller 60 in the apparatus ofthe first embodiment described above. The portion shown in FIG. 4corresponds to a partial cross section, taken in the direction of X--X,of the nursery chamber shown in FIG. 1.

In FIG. 4, reference numeral 20a denotes a light-transmitting coverconstituting the nursery chamber 20, and functions in such a manner asto promote the growth of the plant by allowing the light to betransmitted therethrough. It goes without saying that the illuminator 80mentioned above may be adopted instead of it. In addition, referencenumeral 20b denotes an overall nursery chamber, in which a liquidimpregnation/drainage controller 610 having capillary members 611 isdisposed, and the nutrient broth supports 10 are disposed thereon. Thecapillary members 611 are constituted by a water absorbent material suchas nonwoven fabrics. In addition, the plant bodies T are planted in thenutrient broth supports 10. Although the plant bodies T are illustratedas being seedlings in the drawing, they may be those either at the timeof the above-described culture or at the time of acclimatization to theoutside. Reference numeral 51 denotes the aforementioned liquid transferdevice which is adapted to aseptically supply to the liquidimpregnation/drainage controller 610 the nutrient broth and the likesupplied from the unillustrated nutrient broth supplying device. Inaddition, reference numeral 62 denotes the aforementioned drainingportion, and 63 denotes a valve provided in the draining portion 62.

In accordance with this structure, the nutrient broth supported by(impregnating) the nutrient broth supports 10 as described above isdischarged through the capillary members 611 of the liquidimpregnation/drainage controller 610 and the draining portion 62 whenthe valve 63 is opened. At this time, when the height indicated by H inthe drawing is higher than the peculiar height of rise in the capillarytubes, the liquid contained in the nutrient broth supports 10 isdischarged rapidly through the capillary members 611. That is, theaforementioned liquid replacing action of the liquidimpregnation/drainage controller is attained speedily.

Incidentally, as for the nutrient broth supports 10, a material having arelatively large porosity, such as polyester wool, ceramic wool,cellulose, or the like, is selected, while the capillary members 611constituted by nonwoven fabrics or the like have a small porosity. Sucha difference in porosity between the nutrient broth supports 10 and thecapillary members 611 induces the aforementioned capillary phenomenon,and moves the liquid contained in the nutrient broth supports 10 to thecapillary members 611. In this embodiment, such a phenomenon is inducedonly at the time of drainage when the aforementioned valve 63 is opened,and in a state in which the valve 63 is closed and theimpregnation/drainage controller and the nutrient broth supports 10 arefilled with the liquid, the aforementioned capillary phenomenon based onthe difference in porosity between the nutrient broth supports 10 andthe capillary members 611 does not take place.

In addition, in accordance with the aforementioned liquidimpregnating/draining action of the capillary members 611 capillarilyconnected to the nutrient broth supports 10, it becomes possible to moreeffectively realize not only the aforementioned washing effect but alsocontrol of the water content in the nutrient broth supports 10. Forinstance, in cases where the roots of plants have grown in a state of anexcess water content, degeneration of roots due to the excess watercontent, which is called culture roots, is liable to occur, so that itis necessary to increase the gaseous phase rate of the nutrient brothsupports 10 and set their conditions as the same conditions of generalsoil. In accordance with such a structure of capillary connectionbetween the nutrient broth supports 10 and the capillary members 611,control of the water content becomes possible in which the liquid iscaused to be saturated in the nutrient broth supports 10 at the time ofimplantation, and their gaseous phase rate is increased while the watercontent is gradually decreased from the nutrient broth supports 10 incorrespondence with the subsequent state of rooting, on the basis ofcontrol of the liquid supplied through the liquid transfer device 51 andcontrol of the opening and closing of the valve 63. It should be notedthat although dense fibers are suitable as the capillary members 611, itis possible to use ceramics.

In the second embodiment shown in FIG. 4, the liquid replacing functionof the liquid impregnation/drainage controller is enhanced by capillarydraining which makes use of gravity. The structure of further enhancingthe liquid replacing function based on a similar principle is shown inFIG. 5 as a third embodiment.

In the apparatus of the third embodiment shown in FIG. 5, the amount ofliquid discharged per hour is increased in comparison with the apparatusof the second embodiment by providing draining portions 62a and 62b onopposite sides of the nursery chamber 20 (a main body 20a of the nurserychamber), respectively. In FIG. 5, reference numeral 620 denotes theliquid impregnation/drainage controller, while 621 denotes the capillarymembers provided therein.

In accordance with the capillary gravity draining systems shown as thesecond and third embodiments, even if there are some foams, the drainingfrom the nutrient broth supports 10 is continued insofar as there is anyslightest capillary communication. Accordingly, the amount of the liquidthat finally remains in the nutrient broth supports 10 is extremelysmall. Moreover, it suffices if the nutrient broth supports 10 aremerely placed on the capillary members 611 or 621, and no airtightnessis required.

FIG. 6 illustrates the structure in cases where draining is effected byusing a suction system based on negative pressure.

In FIG. 6, reference numeral 630 denotes the liquidimpregnation/drainage controller; 631, a support member for the nutrientbroth supports 10 and constituted by a wire net or the like; 632,capillary members; and 64, a vacuum pump. Specifically, in this fourthembodiment, water which has permeated the capillary members 632 issucked by the vacuum pump 64. In this case, however, when the water issucked under negative pressure from the valve 63 side, the liquid can bedrained when the capillary members 632 and the main body 20a are inclose contact with each other. Should an air passage be formedtherebetween even at one location, the suction effect is lost, anddraining is not carried out. Accordingly, in this case, suction iseffected at a speed below the speed of the capillary movement so thatthe liquid will be filled uniformly in the capillary members 632. Thisstructure also makes it possible to enhance the liquid replacingfunction of the liquid impregnation/drainage controller 630.

In each of the second to fourth embodiments as well, optimizationcontrol with respect to the gas, temperature, humidity, light quantityinside the nursery chamber 20 as well as sterilization can be effectedin the same way as the first embodiment shown in FIG. 1.

FIGS. 7 and 8 illustrate a fifth embodiment of the culture apparatus inaccordance with the present invention. This fifth embodiment is arrangedwith a view to further promoting the automatic operation of theapparatus of the first embodiment shown in FIG. 1.

First, FIG. 7 illustrates the concept of the arrangement of theapparatus in accordance with this fifth embodiment.

That is, in this fifth embodiment, the arrangement provided is asfollows: After a first door 24a is opened and the nutrient broth support10 is carried into a sterilization entrance section 22, the nutrientbroth support 10 is subjected to sterilization by steam heating or thelike, and a nursery chamber opening/closing door 24b, which is a seconddoor, is then opened before it can be carried into the nursery chamber20 by means of a conveying device 100. At that juncture, theaforementioned support container 11 can also be carried insimultaneously together with the nutrient broth support 10, as required.Subsequently, the second door 24b is closed, the first door 24a isopened, an ensuing nutrient broth support 10 is carried into theentrance section 22. Thus, by alternately operating the first door 24aand the second door 24b, i.e., such that one door is opened when theother door is closed, the necessary material (nutrient broth support 10)can be aseptically carried into the nursery chamber 20. As theaforementioned conveying device 100, it is possible to employ a conveyortype, a robot arm type, a traveling crane type, or the like, asrequired.

Meanwhile, after the nutrient broth support 10 is sterilized or carriedinto the nursery chamber 20, the plant body T is aseptically implantedon the nutrient broth support 10 by the automatic implanting device 30and the implanting mechanism 40 such as those shown in FIG. 3.

In the nursery chamber 20, the plant bodies T are cultured on the basisof a fixed system or a transfer system. At the time of culture, anoptimum nutrient broth medium, gas (air with CO² added thereto), andlight (artificial light or sun light) corresponding to each stage ofculture are supplied by means of the nutrient broth supplying device 50,gas supplying device 70, and the illuminator 80, and the temperature andhumidity are also optimally controlled in the same way as the firstembodiment. With respect to the respective items of control, in the caseof the fixed system, each item is controlled with the lapse of time atthe same position utterly in the same way as the first embodiment. Inthe case of the transfer system, however, the nursery chamber 20 isdivided into a plurality of chambers in advance in correspondence withthe stages of culture, and as the position of the nutrient broth support10 (plant body T) is moved forwardly (in the direction of the arrow)with progress in the stage of culture, control is effected incorrespondence with a corresponding stage of culture for each dividedchamber.

When the plant body T has thus become a seedling of an appropriate size,acclimatization control (lowering of humidity, an increase inillumination intensity, etc.) for acclimatizing the plant body T to theexternal environment is carried out as a final stage. At this juncture,an operation such as washing for removing nutrients contained in themedium by means of the liquid impregnation/drainage controller (notshown for the convenience' sake) or the like is conducted, as required.

Next, the nutrient broth support 10 (plant body T) is moved to abacteria-proof exit section 23. This exit section 23 is provided with anexit opening/closing door 24c for the nursery chamber as well as an exitopening/closing door 24d for exit from the exit section. Theseopening/closing doors 24c and 24d and the conveying device 100 areinterconnected with each other in the same way as the first and seconddoors 24a and 24b. Immediately after the plant body T which has become agrown seedling is placed in the exit section 23, the plant body T iscarried out to the outside in a state in which the entrance of variousbacteria into the nursery chamber 20 from the outside is preventedthrough a combination of a heating sterilizing device or a bacteriaproof device or the like making use of an air flow as well as the doors24c and 24d.

FIG. 8 illustrates an example of the arrangement of the above-describedapparatus in accordance with the fifth embodiment, and in particular thecase of the transfer type is illustrated here. In FIG. 8, elements thatare identical with those shown in FIG. 1 or functionally correspondthereto are shown by being denoted by identical or correspondingreference numerals.

In the apparatus of this embodiment, the nutrient broth support 10together with the container 11 accommodating the same is carried inthrough the carrying-in port 22 and is subjected to sterilization byheating by means of a heating sterilizing device 91. Then, the door 24bis opened by the conveying device 100 of a pusher type, and the nutrientbroth support 10 is introduced into a first nursery chamber 201 by theconveying device 100. At that juncture, all the nutrient broth supports10 situated in respective nursery chambers 201, 202 and 203 are movedsimultaneously to enter the respective ensuing stage of culture.

The plant body T is implanted on the nutrient broth support 10 which hasentered the first nursery chamber 201 by means of the automaticimplanting device 30 and the implanting mechanism 40.

Here, a nutrient broth medium and a gas that are suitable for each stageof culture are supplied to the aforementioned nursery chambers 201, 202and 203 by means of respective liquid transfer devices 511, 512 and 513as well as gas transfer devices 711, 712 and 713, and a suitable amountof light is supplied to them by means of each illuminator 80. Althoughan illustration is omitted here, respective liquid impregnation/drainagecontrollers are connected to the liquid transfer devices 511, 512 and513 so as to effect the transmission and reception (replacement) of theliquid with respect to the corresponding nutrient broth supports 10 ineach nursery chamber in the above-described manner. As these liquidimpregnation/drainage controllers, it is possible to employ those shownin the first to fourth embodiments.

The plant body T (nutrient broth support 10) for which the finalacclimatization processing has been completed is taken out through thecarrying-out port 24 as the plant body T (nutrient broth support 10) ispushed out, as described above. At that juncture, an arrangement isprovided such that bacteria and the like will not enter the nurserychamber 20 (203) by means of a bacteria-proof air curtain device 92.Reference numeral 24c denotes the exit opening/closing door for thenursery chamber which is pushed open by means of the nutrient brothsupport 10 placed in the third nursery chamber 203 as it is pushed out,as described above.

It should be noted that, in addition to this transfer type, by using afixed type (automated only with respect to the carrying in and out ofthe nutrient broth supports into the nursery chamber) using a travelingcrane-type robot or the like, culture may be continued at the sameposition and various control elements may be controlled with the lapseof time in correspondence with the stage of culture that changes withtime, as described before.

FIG. 9 illustrates a sixth embodiment of the culture apparatus inaccordance with the present invention. In this sixth embodiment, thestructures of the liquid transfer device and the gas transfer device, inparticular, of the apparatuses of the embodiments hitherto shown areembodied so that these devices can be detachably connected to thenursery chamber while maintaining an aseptic state. It should be notedthat, in FIG. 9 as well, elements that are identical to those shown inthe preceding drawings or functionally correspond thereto are shown bybeing denoted by identical or corresponding reference numerals.

In this sixth embodiment, the nursery chamber 20 for accommodating thenutrient broth supports 10 has its top portion constituted by a cover20b having a hermetically closable structure and formed oflight-transmitting plastics or glass. This cover 20b is arranged suchthat it is held in close contact with the main body 20a of the nurserychamber by means of springs 20c and receiving plates 20d of the mainbody 20a. The main body 20a of the nursery chamber is connected to thenutrient broth supplying device 50 via the liquid transfer device 51having a nutrient broth joint 51b which can be sterilized, while thecover 20b is connected to the gas supplying device 70 via the gastransfer device 71 having a gas joint 71b which can be sterilized. Thesejoints 51b, 71b are structured in such a manner that they can behermetically closed even when they are not connected, as will bedescribed later. In addition, the liquid impregnation/drainagecontroller 60 on which the nutrient broth supports 10 are mounted hasits upper surface formed of a porous material such as a wire net, as hasbeen described in connection with the first embodiment. The arrangementis such that the ratio between the amount of nutrient broth and theamount of gas in the nutrient broth supports 10 and so on can beadjusted by controlling the level of the nutrient broth supplied to theliquid impregnation/drainage controller 60. It should be noted that thetype shown in the second to fourth embodiments may, of course, be usedas the liquid impregnation/drainage controller, which further enhancesthe liquid replacing function thereof, as described before.

A description will now be given of the structures of the nutrient brothjoint 51b and the gas joint 71b.

As illustrated, the nutrient broth joint 51b is a combination of a pairof flanges 51c, which are suitably connected together, and a pair ofstop valves 51d disposed on opposite sides thereof. In addition, the gasjoint 71b is similarly a combination of a pair of flanges 71c, which aresuitably connected together, and a pair of stop valves 71d disposed onopposite sides thereof. Incidentally, reference numeral 51a denotes amain body of the liquid transfer device constituted by a pipe product orthe like, while numeral 71a denotes a main body of the gas transferdevice similarly constituted by a pipe product or the like. Thus, sincethe joints 51b, 71b are constructed as a combination of the flanges andthe stop valves disposed on opposite sides thereof, after both the stopvalves are closed, if the stop valves are separated from each other withthe flanges serving as a boundary, it is possible to separate thenutrient broth supplying device 50 from the nursery chamber 20 (the mainbody 20a of the nursery chamber), and the gas supplying device 70 fromthe nursery chamber 20 (the cover 20b) in a state in which the shieldedstate of the nutrient broth supplying device 50, the gas supplyingdevice 70, and the nursery chamber 20 is maintained. The nursery chamber20 thus removed as a set by being separated from the nutrient brothsupplying device 50 and the gas supplying device 70 can be separatelysubjected to sterilization treatment by such as being placed in anautoclave heat sterilizer. The section which can thus be removed as aset is shown as a section P in FIG. 9.

Accordingly, in the apparatus in accordance with this sixth embodiment,after the joints 51b, 71b are separated and the seedlings are taken outby removing the cover 20b from the main body 20a of the nursery chamber,the cover 20b, the main body 20a, the nutrient broth supports 10, andthe like can be separately subjected to sterilization. In addition,after the plant body T (not shown) is implanted and accommodated, theplant body T can be hermetically sealed in the nursery chamber 20 in anaseptic state by means of the cover 20b.

When the nursery chamber 20 is connected to the nutrient broth supplyingdevice 50 and the gas supplying device 70, the connection is effectedvia the respective joints 51b and 71b, as described above. At thisjuncture, since aseptic communication is established with thesesupplying devices, the interior of the communicating portions with thesesupplying devices are subjected to sterilization treatment by means ofheating such as by being burnt with a heater. Incidentally, abacteria-proof filter 70b for the gas is used on the gas-supplying side,and a tank which has been sterilized in advance is used as a nutrientbroth tank 50b. In addition, with respect to the gas exhausting device72 and the draining portion 62 as well, it is possible to adopt asimilar structure, as required. In FIG. 9, reference numeral 50a denotesan inlet valve for the nutrient broth tank 50b; 50c, a pump; 63, thedraining valve; 70a, a gas mixer; 72a, a main body of the gas exhaustingdevice; and 72b, an exhaust filter. The waste liquid via the valve 63may be disposed of, or may be allowed to communicated with the nutrientbroth tank 50b so as to be returned thereto in an aseptic stage, asnecessary.

FIG. 10 illustrates a seventh embodiment of the present invention. Thisseventh embodiment represents, in a way, a composite arrangement of theapparatuses of the embodiments shown in the above. In FIG. 10 as well,elements that are identical with those shown in the previous drawings orfunctionally correspond thereto as shown by being denoted by identicalor corresponding reference numerals.

In this seventh embodiment, reference numeral 2000 denotes a culturerack assembly which is provided with a plurality of, i.e., six in theillustrative case, nursery chambers (two units each of the first tothird nursery chambers 201-203). In this embodiment, optimum control ofthe nutrient broth and the gas is effected collectively in conformitywith the stage of culture for each nursery chamber by means of the threenutrient broth supplying devices 501-503 and the gas supplying devices701-703. Here, reference numeral 80 denotes the illuminator; 500, acontroller for the nutrient broth supplying device; and 700, acontroller for the gas supplying device.

In the implementation of the apparatus of this embodiment, the followingdiverse variations are conceivable, and they may be selectedarbitrarily.

(1) The relationship of correspondence between the nursery chambers201-203 and the supplying devices 501-503 and 701-703 is madearbitrarily changeable by adopting the joints shown in the sixthembodiment (FIG. 9) for the transfer devices 511-513 and 711-713 and thecirculators 521-523.

(2) The transfer devices are used by being fixed between the supplyingdevices and the nursery chamber (regardless of whether or not theaforementioned joints are used).

(3) The first to third nutrient broth supplying devices 501-503 are alsoused exclusively in a corresponding manner with respect to the gassupplying devices 701-703 that are used exclusively for supplying thegermination nutrient broth, the rooting nutrient broth, and thecultivation nutrient broth, respectively.

(4) In the first to third nutrient broth supplying devices 501-503, thesupply of the germination nutrient broth, the supply of the rootingnutrient broth, and the supply of the cultivation nutrient broth areeffected with the lapse of time in correspondence with the stage ofculture, respectively, as described above.

In addition, in FIG. 10, an apparatus is shown which is of a circulationtype in which the discharged nutrient broth is returned to nutrientbroth tanks 501b-503b via the circulators 521-523, these circulators maybe eliminated. In addition, in cases where the circulation type isadopted, it is possible to remove harmful components by using purifierssuch as filters inside the circulators 521-523 or the tanks 501b-503b.

Thus, in accordance with the foregoing embodiments, without using anagar medium and by using porous or fibrous nutrient broth supports withgood water retentivity and air permeability as well as the nutrientbroth medium, it is possible to change the nutrient broth componentsinto optimum components at each level of culture while constantlymaintaining the overall apparatus in an aseptic state and withoutrequiring any operation for transplanting.

It should be noted that, in the apparatuses of the first to seventhembodiments, a combination thereof is arbitrary, and the selection ofthe various elements in arranging the apparatus may be effected freelywithin the range in which the purport of the present invention isbasically maintained. Favorable elements should be selected in therespective situations.

For instance, as the nursery chamber 20, there is a type which requiresthe implanting device and the illuminators such as those shown in FIGS.1 and 8, and there is a type which is provided with a light-transmittingcover such as the one shown in FIGS. 4-6 and 9 and does not necessarilyrequire the implanting device and the illuminators.

In addition, with respect to the liquid impregnation/ drainagecontroller 60 (610-630) as well, the selection of its type is arbitrary.In particular, in cases where a plurality of nursery chambers such asthose shown in FIGS. 8 and 10 are used, it is possible to adoptdifferent types of liquid impregnation/drainage controller depending onthe usage of culture of these nursery chambers. Incidentally, the liquidimpregnation/drainage controllers 610-630 such as those shown in FIGS.4-6 are favorable in cases where washing processing with pure watermentioned above is also carried out.

The nutrient broth supplying device 50 may be provided with anarrangement in which a plurality of tanks for separately storing thevarious nutrient broths and pure water are provided. Alternatively, anarrangement may be provided such that these various nutrient broths andpure water are changed over and stored in a single tank. Theseselections are also arbitrary.

In addition, there can be cases where the gas supplying device 70 is notnecessarily required, depending on the environment where the nurserychamber is placed. That is, there are cases where a desired gasenvironment can be obtained simply by providing a ventilation hole orthe like in the nursery chamber. In such a case, the gas supplyingdevice 70 may be eliminated.

The same holds true of the control of the internal temperature andhumidity of the nursery chamber. In addition, depending on the case, atemperature and humidity controller may be disposed separately in thenursery chamber.

INDUSTRIAL APPLICABILITY

In accordance with the present invention, the processing of a plantbody, such as breeding, fostering of seedlings, and acclimatization tothe outside can always be realized under an optimum environment in anaseptic state.

In addition, since no transplanting operation is required, substantialmanpower can be dispensed with, and roots are not subject to damage, sothat the time and cost involved in producing seedlings from the tissueof a plant body can be reduced, and consequently the high-speed,large-scale production and development of new plant varieties can beconducted efficiently.

In addition, the present invention is applicable to the culture of notonly plant bodies but also adhesive animal cells, and has extensiveusage.

We claim:
 1. A liquid culture apparatus comprising:a nutrient brothsupport for supporting a plant body implanted therein and comprising aporous or fibrous material having a first porosity capable of absorbinga nutrient broth and bringing said broth into contact with said plantbody; a nursery chamber for enclosing at least one said nutrient brothsupport in a controlled environment; first liquid controlling means forstoring liquids such as various types of nutrient broths needed forvarious stages of plant growth such as germination and/or rooting brothsand other liquids such as water and for supplying said liquids to saidnursery chamber; second liquid controlling means comprising a liquidabsorbant material having a second nursery which is smaller than saidfirst porosity of said nutrient broth support, for supporting saidnutrient broth support and receiving said liquid supplied to saidnursery chamber by said first liquid controlling means and coupling saidliquid to said nutrient broth support such that said nutrient brothsupport absorbs said liquid and brings said liquid into contact withsaid plant body, and, when said first liquid controlling means stopssupplying said liquid, for receiving liquid which drains from saidnutrient broth support; third liquid controlling means coupled toreceive said drained liquid from said second liquid controlling meansfor draining said liquid through a path leading to a point outside saidnursery chamber.
 2. The apparatus of claim 1 wherein said liquid storedin said first liquid controlling means comprises a selected one ofgermination nutrient broth containing nutrient components effective foraiding in germination of said plant body implanted in said nutrientbroth support, a rooting nutrient broth containing nutrient componentseffective for aiding the process of rooting by said plant body, acultivation nutrient broth containing nutrient components effective forfostering growth of said plant body, said cultivation nutrient broth notcontaining sugar, or water for washing said plant body or roots thereofat predetermined times in the growth of said plant body, and whereinsaid first liquid controlling means includes means for selectivelysupplying appropriate ones of said liquids to said nutrient brothsupports at appropriate times in the growth of said plant body.
 3. Theapparatus of claim 2 further comprising gas control means coupled tosaid nursery chamber for mixing air and carbon dioxide at apredetermined ratio and supplying the mixture to said nursery chamber asnew gas, and for providing a path through which gas already in saidnursery chamber pushed by said new gas may exit said nursery chamber. 4.The apparatus of claim 1 further comprising means coupled to saidnursery chamber for providing an aseptic environment inside said nurserychamber surrounding said nutrient broth support.
 5. The apparatus ofclaim 1 wherein said nursery chamber is divided into a plurality ofchambers, each chamber corresponding to a stage in the growth of saidplant body, and wherein said first, second and third liquid controllingmeans are coupled to each of said chambers.
 6. The apparatus of claim 5wherein said nursery chamber further comprises individual light sourcemeans for supplying light having a spectrum conducive to growth of saidplant bodies for each of said chambers.
 7. The apparatus of claim 6wherein said light source means comprises individual light bulbs affixedto said nursery chamber in a position to shine light on said plantbodies.
 8. The apparatus of claim 6 wherein said light source meanscomprises a light transmitting portion of said nursery chamber forpassing natural light to said plant bodies.
 9. The apparatus of claim 5,further comprising gas control means coupled to said nursery chamber formixing air and carbon dioxide at a predetermined ratio and supplying themixture to said nursery chamber as new gas, and for providing a paththrough which gas already in said nursery chamber pushed by said new gasmay exit said nursery chamber.
 10. The apparatus of claim 5 furthercomprising conveying means for conveying said nutrient broth supportthrough said nursery chamber.
 11. The apparatus of claim 1 furthercomprising implanting means coupled to said nursery chamber forautomatically implanting said plant bodies into said nutrient brothsupport.
 12. The apparatus of claim 1 further comprising gas supplymeans coupled to said nursery chamber for controlling the ratio ofcarbon dioxide and air inside said nursery chamber.
 13. The apparatus ofclaim 1 wherein said nursery chamber further comprises means forsupplying artificial light having a spectrum suitable for growth of saidplant bodies.
 14. The apparatus of claim 1 wherein said nursery chamberfurther comprises means for allowing artificial light to enter saidchamber.
 15. The apparatus of claim 1 wherein said second liquidcontrolling means include means to drain said liquid from said nutrientbroth support when the level of liquid supplied to said nutrient brothsupport by said first liquid controlling means drops below apredetermined level.
 16. The apparatus of claim 1 wherein said thirdliquid controlling means includes a vacuum pump for sucking liquid outof said nutrient broth support.
 17. A liquid culture apparatuscomprising:a nutrient broth support for implantation of a plant bodytherein and constituted by a porous of fibrous material capable of beingimpregnated with a nutrient broth; a nursery chamber for accommodatingat least one said nutrient broth support; first liquid controlling meansfor transferring and supplying a liquid to said nutrient broth supportaccommodated in said nursery chamber; second liquid controlling meanswhich is constituted by a water absorbant material having a smallerporosity than said nutrient broth support and is disposed at a bottom ofsaid nursery chamber as a member for placing said nutrient broth supportthereon, said second liquid controlling means being arranged such thatwhen a level of the liquid supplied to said nutrient broth support hasdropped below a predetermined level, said second liquid controllingmeans drains the liquid impregnating said nutrient broth support; thirdliquid controlling means connected to said second liquid controllingmeans and adapted to discharge the liquid drained via said second liquidcontrolling means to outside said nursery chamber.
 18. A liquid cultureapparatus according to claim 17 wherein said third liquid controllingmeans has a vacuum pump for sucking and forcedly discharging the liquiddrained via said second liquid controlling means.